Piano-tuning wrench



Sept. 12, 1939. .1;Y H. BRADY PIANO'TUNING WRENCH F'iled March 5, 1938Patented Sept. 12, 1939 UNITED STATES PATENT OFFICE PIAN O-TUNING WRENCHApplication March 3, 1938, Serial No. 193,795

2 Claims.

The invention relates to piano tuning wrenches, an object of theinvention being to provide a practical balanced geared wrench of thisdescription adapted to have more accurate and delicate control of thepins being tuned and t0 lessen the chances of breaking a piano Wire orstring and the chances of loosening the tuning pins in the pin block ofthe piano by too much turning of said pins back and forth inaccomplishing the tuning. Another object is to .adapt the wrench to beswung upwardly and downwardly upon an anchoring pin (not being tuned)with which the wrench is engaged, as a center, to lift the wrench from apin being tuned and engage the same with other pins to be tuned withinthe radius of the body of the wrench and a slide extension thereof,without removal of the wrench from said anchoring pin. Other objects andadvantages will appear hereinafter.

The invention consists in the novel construction and combinations ofparts as hereinafter set forth in the claims.

In the accompanying drawing,

Figure 1 is a side view of the wrench, partly in section, the tuningpins being shown in dotted lines, and the wrench being shown as swungupwardly upon an anchoring pin as a center, .and the slide extensionadjusted for engagement with another pin to be tuned, in dotted lines.

Figure 2 is a bottom plan view of the wrench.

In the drawing, the numeral I designates the body or support, ofelongated form, having fixedly secured within a perforation 2, at oneend thereof the upper end of .a depending sleeve 3, a

tubular shaft 4, rotatably engaging Within said sleeve and having at itslower end a socket piece 5, iixedly secured thereon and adapted toengage a pin the string of which is to be tuned, said tubular shafthaving secured thereon at the upper end thereof a spur gear 6, restingupon said sleeve, a shaft l, rotatably engaging within said tubularshaft and being provided with an upper hand wheel 8, axially alignedwith said socket piece, and a pinion 9, resting upon said spur gear. Thebody or support I has a stud i0, with which a pinion II and a spur gearI2 resting upon said support have rotatable engagement, said pinion ,andspur gear meshing respectively with the rst named spur gear and pinion,and being secured together to act as a unit. The support or body I isalso provided with an elongated slide extension I3, the longitudinaledges of which are tapered to adapt said extension to engage adovetailed groove I4 of said support, 55 said extension being providedat the free end thereof with a depending socket piece I5, adapted toengage another pin the string of which is to be tuned for anchoringpurposes, said socket piece I5 having an upper reduced stem I6projecting above the extension to form a handle or finger 5 piece andhaving threaded engagement with a perforation of the extension.

'I'he recess I'I of the socket piece I5 is of such oval or elongatedform in cross section as to adapt the entire wrench to be swung upwardly10 and downwardly upon the anchoring pin as a center to lift the wrenchfrom the pin the string of which is being tuned and engage the wrenchwith other pins the strings of which are to be tuned, Within the radiusof said support and its slide extension, without removal of the wrenchfrom the anchoring pin. A pin I8 of said support engages a groove I9 ofsaid extension to limit the movement of the latter in both directions.The rotatable shaft l is provided at its 20 lower end with acircumferential groove 20, with which a radial screw 2l of the socketpiece 5 has engagement at its inner end, and upon removal of said screw,the shaft l, its hand wheel and pinion, may be removed. 25

The support or body I of the wrench and its slide extension I3 are bothof generally flat or planular form and when the slide extension isadjusted inwardly, the inner end of said extension is located adjacentthe depending sleeve 3, 30 and the depending socket piece I5 adjacentthe outer end of said body, the dimensions of the parts being such as tobe readily handled and controlled.

The parts being all centrally located with re- 35 spect to a singlevertical plane and the socket piece 5 and the hand wheel 8 being axiallyaligned with each other, accurate tuning and delicate control arefacilitated, being essential for a precision instrument of thisdescription. 40 The hand wheel 8 being round and having acircumferential covering of rubber is always in the same position incontrast to a T-form handle, and is more readily grasped by the thumband two or three ngers o'f one hand. The depend- 45 ing socket piece I5at the free end of the slide extension aids in holding the Wrench instationary upright position when in use.

In using the wrench, the socket piece 5, the recess of which ispreferably of octagonal or star shape in cross section, is slipped onthe pin the string of which is to be tuned, and the slide extension I3being pulled out fully, the socket piece I5 thereof is slipped on themost distant pin that it will engage to hold or anchor the wrench in oneposition while the hand wheel is being turned to accomplish the tuning,following which the wrench is swung upwardly on the anchoring pin as acenter to disengage the wrench from the pin the string of which has beentuned, without removal of the socket piece i5 from the .anchoring pin,and then swung downwardly on the anchoring pin as `a center to engagethe next pin the string of which is to be tuned, this procedure beingfollowed to tune those strings the pins of which are within the limitsof the adjustment of the wrench.

I claim:

l. In a piano tuning wrench, a support having a depending sleeve, atubular shaft rotatably engaging said sleeve and having a socket pieceadapted to engage a pin to be tuned and a spur gear resting upon saidsleeve, a shaft rotatably engaging within said tubular shaft andprovided with an upper hand wheel axially aligned with said socket pieceand a pinion resting upon said spur gear, said support having a stud,and a pinion and a spur gear rotatably engaging said stud and meshingrespectively with said rst named spur gear and pinion, said supporthaving a slide extension provided with a depending socket piece adaptedto engage another tuning pin for anchoring purposes, the parts being allcentrally located with respect to a single vertical plane.

2. In a piano tuning wrench, a support having a depending sleeve, atubular shaft rotatably engaging said sleeve and having a socket pieceadapted to engage a pin to be tuned and a spur gear resting upon saidsleeve, a shaft rotatably engaging within said tubular shaft andprovided with an upper hand wheel axially aligned with said socket pieceand a pinion resting upon said spur gear, said support having a stud,and a pinion and a spur gear rotatably engaging said stud and meshingrespectively with said rst named spur gear and pinion, said supporthaving a slide extension provided with a depending socket piece adaptedto engage another tuning pin for anchoring purposes, the parts being allcentrally located with respect to a single vertical plane, the recess ofthe last named socket piece being of such elongated form in crosssection as to adapt the entire device to be swung upwardly anddownwardly upon the anchoring pin as a center to lift the wrench fromthe pin being tuned and engage the same with other pins to be tunedwithin the radius of said support and its slide extension.

JAMES HENRY BRADY.

